1. Field
Various features relate to a toroid inductor in redistribution layers of an integrated device.
2. Background
A typical die is manufactured by depositing several metal layers and several dielectric layers on top of a substrate. The die is manufactured by using a wafer level packaging (WLP) process. FIG. 1 illustrates a side view of a wafer. Specifically, FIG. 1 illustrates a side view of a portion of a wafer 100. The wafer 100 includes several metal and dielectric layers 102, a pad 104, a passivation layer 106, a first insulation layer 108, a first metal layer 110, a second insulation layer 112, and an under bump metallization (UBM) layer 114. FIG. 1 also illustrates a solder ball 116 on the wafer 100. Specifically, the solder ball 116 is coupled to the UBM layer 114. The pad 104, the first metal layer 110 and the UBM layer 114 are a conductive material (e.g., copper). The first insulation layer 108 and the second insulation layer 112 are polyimide layers (PI), Polybenzoxazole (PBO) or other polymer layers used for repassivation.
In some electronic designs, an inductor may be required. In a traditional electronic design, the inductor may be placed outside of the package. For example, the package that includes a die may be coupled to a printed circuit board (PCB). An inductor may be coupled to the PCB. Thus, the inductor may be coupled to the package that includes a die through the PCB. One downside of this approach is that the inductor may be far away from die. In some instance, it may be ideal and/or optimal to have the inductor as close as possible to the die. For instance, it may be ideal and/or optimal to have the inductor coupled to the die and/or die package, while at the same time bypassing a PCB. In some implementations, it may be desirable to put an inductor in the metal and dielectric layers of the die. However, such a solution would increase the Si die area as the inductor may cause electromagnetic interference with the active elements and/or circuits of the die.
Therefore, there is a need for a design that provides an inductor (e.g., toroid inductor) in an integrated device (e.g., a die, die package).